null in template_preprocess_image_style()

+++ b/core/modules/image/image.module
@@ -294,39 +294,47 @@ function image_style_options($include_empty = TRUE) {
+  } else {

Nice work! Makes sense.
Instead of adding another else here, we could do an early return.

This would make the code a little less complex.
Also this would make the patch a lot smaller:

diff --git a/core/modules/image/image.module b/core/modules/image/image.module
index 4c0e8cca99..3e1601d9c6 100644
--- a/core/modules/image/image.module
+++ b/core/modules/image/image.module
@@ -294,6 +294,14 @@ function image_style_options($include_empty = TRUE) {
 function template_preprocess_image_style(&$variables) {
   $style = ImageStyle::load($variables['style_name']);
 
+  if (!$style) {
+    \Drupal::logger('image')->warning('Image style (@style) missing for @image. Please add the missing style under /admin/config/media/image-styles.', [
+      '@style' => $variables["style_name"],
+      '@image' => $variables['uri'],
+    ]);
+    return;
+  }
+
   // Determine the dimensions of the styled image.
   $dimensions = [
     'width' => $variables['width'],

I encountered a problem with the Simple Login module (#3166927)- the patch at #3 sorted this issue out.

I can also confirm that patch #3 works as expected.

I have applied the patch #3 and it works fine after applying the patch.

After reconsideration this does not significantly impacts ( only one ) subsystem. Removing the tag.
Thanks for @lauriii for pointing this out on slack.

I can confirm patch #3 works.

This looks like a nice fix but I am pretty sure this will need a test. And let's use the issue summary template and explain the proposed resolution.

Is this still an issue for 8.9.15? Trying to determine if I should use #3.

Re-rolled this against 9.3.x from #3

The patch is working fine after the patch i am able to access site for ref sharing screenshot

This may be a duplicate of #2957368: Call to a member function transformDimensions() on null in template_preprocess and #3145187: Default image + No preview = fatal error?

If this isn't a duplicate, adding "Needs steps to reproduce", just to ensure that is taken into account when "needs issue summary update" is addressed.

Similarly, #16 Does not provide any new information, just what was already provided in the issue summary but as a screenshot instead of code snippet.

@bnjmnm #17 - Thought the same. I think #2957368: Call to a member function transformDimensions() on null in template_preprocess is related, just affecting another preprocess function.